Xu Tiancheng, 56, uses "Qi Gong" or "Internal Energy" to practice a headstand on a flat nail at a pedestrian street in Wuhan, Hubei province March 16, 2012. According to Xu, he has been practising "Qi Gong" for more than 5 years. REUTERS/Stringer

Xu Tiancheng, 56, uses "Qi Gong" or "Internal Energy" to practice a headstand on a flat nail at a pedestrian street in Wuhan, Hubei province March 16, 2012. According to Xu, he has been practising "Qi Gong" for more than 5 years. REUTERS/Stringer